In 1911, the Irrigation Investigations Unit (IIU) of the U.S. Department of Agriculture was established in Fort Collins in conjunction with Colorado Agricultural College (now Colorado State University). Scientists within the unit studied and designed apparatuses to measure water flow through canals and diversion structures, investigated various irrigation projects, and conducted snow surveys. The Irrigation Research Papers collection includes letters, data, field books, drafts, reports, blueprints, maps, conference materials, photographs, and negatives. For more information see the finding aid.

This digital collection, with materials dated 1903 to 1956, includes more than 3,100 images as well as correspondence, data, reports, and conference materials generated by IIU staff during their investigations.

Recent Submissions

  • 81. The exchange system of irrigation waters as applied to Colorado, August 1921 

    Creator(s):Parshall, Ralph L. (Ralph Leroy), 1881-1959, author
    Date:1921-1922
    Format:maps (documents); reports
    Includes "The exchange system of irrigation waters as applied to Colorado" by Ralph L. Parshall, August 1921, focusing on the Cache la Poudre Basin; drafts of "Exchange of water"; and "Irrigation District of Northern ...
  • 118. Discharge table and proportion table for Lake Canal, Fort Collins 

    Creator(s):Cone, Victor M. (Victor Mann), author
    Date:1924-1926; undated
    Format:documents (object genre); bulletins; reports
    Includes Farmers' Bulletin 813: Construction and use of farm weirs by Victor M. Cone, Irrigation Engineer, Bureau of Public Roads. Typed and written tables: Discharge in second-feet per share or fraction there of according ...
  • 19. Professional paper, manuscripts, Flow over weirs with sharp crests and full contractions 

    Creator(s):Murdock, Harvey E. (Harvey Ellison), -1956, author; Cone, Victor M. (Victor Mann), author
    Date:1914; undated
    Format:documents (object genre); reports
    Annotated draft of a professional paper: Flow over weirs with sharp crests (thin edges) and full contractions. The first page has been notated at the top-right with "V. M. Cone". Letter from H. E. Murdock of Irrigation ...
  • 23. Rectangular weir tables - original and revised 

    Creator(s):Unidentified author
    Date:1915; undated
    Format:documents (object genre)
    Typed and handwritten tables pertaining to rectangular weirs.
  • 22. Cipolletti weir tables - original and revised 

    Creator(s):Unidentified author
    Date:1915; undated
    Format:documents (object genre)
    Typed and handwritten tables pertaining to Cipolletti weirs.
  • 290. Manuscripts, "Improved Venturi flume" 

    Creator(s):Parshall, Ralph L. (Ralph Leroy), 1881-1959, author; Unidentified photographer
    Date:1927; undated
    Format:photographs; documents (object genre); reports; blueprint (reprographic copies)
    R.L. Parshall's paper, Improved Venturi Flume, was prepared under direction of W. W. McLaughlin, Associate Chief, Division of Agricultural Engineering, and includes photographs, diagrams, charts, tables, and a blueprint ...
  • 292. Discussion of paper by Yarnell and Nagler on effect of turbulence on cup and propeller meters, 1930 

    Creator(s):Yarnell, D. L., author
    Date:1930; undated
    Format:documents (object genre); reports; correspondence
    Two drafts of a discussion paper of Carl Rowher's Effect of Turbulence on the Registration of Current Meters; a letter from D. L. Yarnell, Senior Drainage Engineer, Bureau of Public Roads, United States Department of ...
  • 290. Printer's copy, Improved Venturi flume, revised December 1927 

    Creator(s):Parshall, Ralph L. (Ralph Leroy), 1881-1959, author
    Date:1927; undated
    Format:reports
    Draft of R.L. Parshall's paper, Improved Venturi Flume, was prepared under direction of W. W. McLaughlin, Associate Chief, Division of Agricultural Engineering, with tables.
  • 286. Amity 20-foot flume, notes concerning new floor, March 1938 

    Creator(s):Burgess, L. T., author; Parshall, Ralph L. (Ralph Leroy), 1881-1959, author; Hinderlider, M. C. (Michael Creed), 1876-1967, author
    Date:1937-1938; undated
    Format:documents (object genre); correspondence
    Contains a letter from L. T. Burgess, Chief Hydrographer for the Engineering Department of the State of Colorado, to Ralph Parshall concerning tabulations of snow survey measurements made at the east portal of Moffat Tunnel ...
  • 287. Laboratory measurement of evapo-transpiration losses 

    Creator(s):Parshall, Ralph L. (Ralph Leroy), 1881-1959, author; Ewing, Paul A., author; Kittredge, Joseph, 1890-1971, author
    Date:1937
    Format:documents (object genre); correspondence; presentations (communicative events); reports
    Includes letters, marked drafts, and notes related to two included papers that R. L. Parshall presented at conventions: Laboratory measurement of evapo-transpiration losses and Irrigation water resources of Colorado. There ...
  • 289. Radio broadcast, February 19, 1935, KOA 

    Creator(s):Rohwer, Carl, author; Mitchelson, A. T., author; McLaughlin, W. W., author
    Date:1935
    Format:documents (object genre); reports; correspondence
    Includes drafts of Carl Rohwer's, How to Get the Most out of a Limited Supply of Irrigation Water. A. T. Mitchelson, Senior Irrigation Engineer, Division of Irrigation, Bureau of Agricultural Engineering for the United ...
  • 297. Publication material supporting irrigation research, 1934 

    Creator(s):Parshall, Ralph L. (Ralph Leroy), 1881-1959, author; McLaughlin, W. W., author; Douglas, L. W., author; Hays, Robert, author; Pointer, Vena, author; Colwell, Charles I., author; Young, A. A., author
    Date:1934; undated
    Format:documents (object genre); correspondence; reports; journals (periodicals); clippings (information artifacts)
    Multiple letters related to irrigation research and federal funding include: from Parshall to Rohwer; from W. W. McLaughlin to R. L. Parshall; from L. W. Douglas to Senator McAdoo; from Parshall to Lory and Rohwer; from ...
  • 284. Automatic sand sampling device, 1939 

    Creator(s):Unidentified author
    Date:undated
    Format:blueprints (reprographic copies)
    Envelope and blueprint of the cycle of operation of an automatic sand sampling device.
  • 285. Acre-foot integrating instrument, May 1938 

    Creator(s):Unidentified author
    Date:undated
    Format:documents (object genre)
    Envelope and tables concerning an acre-foot integrating instrument.
  • 295. Manuscripts, "Large Parshall measuring flumes" 

    Creator(s):Parshall, Ralph L. (Ralph Leroy), 1881-1959, author; Unidentified photographer
    Date:1931-1932
    Format:photographs; reports
    Contains two copies of R. L. Parshall's report, Large Parshall Measuring Flumes, prepared under the direction of W. W. McLaughlin. One is an annotated draft and the other copy includes photographs.
  • 296. Submerged flow measurements on Bijou flume, July 1932 

    Creator(s):Parshall, Ralph L. (Ralph Leroy), 1881-1959, author; Scobey, Fred C. (Frederick Charles), 1880-1962, author; McLaughlin, W. W., author
    Date:1932; undated
    Format:informaton forms (objects); corresopndence; field notes; memorandums
    A field notebook with submerged flow measurements on the Bijou Flume by Parshall, Brooks, and McGraw; letters from W. W. McLaughlin to R. L. Parshall concerning the Bijou and Holbrook flumes, as well as the Fort Lyon Canal; ...
  • 294. Free-flow discharge tables, Parshall measuring flumes, large size, 20 feet, 25 feet, 30 feet, 40 feet, and 50 feet 

    Creator(s):Unidentified author
    Date:undated
    Format:documents (object genre)
    Free-flow discharge tables of Parshall measuring flumes: 20 ft., 25 ft., 30 ft., 40 ft., and 50 ft.
  • 283. Elements of Q curves 

    Creator(s):Scobey, Fred C. (Frederick Charles), 1880-1962, author; Amsley, H. D., author; Owens, A. Ralph, author
    Date:1933-1935; undated
    Format:documents (object genre); correspondence; blueprints (reprographic copies)
    H. D. Amsley of the Fort Lyon Canal Company wrote letters to R. L. Parshall concerning a proposed pipeline across Horse Creek for the Fort Lyon canal. A. Ralph Owens of The Twin Lakes Reservoir and Canal Co. also wrote to ...
  • 248. Silt Experiments made in India, summary of report and drawings of silt vanes 

    Creator(s):Vaidhianathan, V. I., author; Sharma, Pandit K. R., author; King, H. W., author
    Date:undated
    Format:documents (object genre); blueprints (reprographic copies); proceedings (reports)
    Blueprint drawings, tables, directions, and proceedings related to silt vanes, siltometer, conduction, and exclusion.
  • 247. Simplex totalizing, indicating meter for Parshall measuring flume 

    Creator(s):Glover, W. W., author
    Date:1935-1936; undated
    Format:documents (object genre); correspondence; blueprints (reprographic copies)
    Letter, directions, blueprints, sales form, and packing list to R. L. Parshall from W. W. Glover of Simplex Valve and Meter Co. of Philadelphia concerning a Simplex-Parshall Venturi flume meter.

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